Aleph5 more mosfet output

[tanwa]

Hello,
I am building Aleph5 and I want to add more output mosfet without changing of the bias per device. So, I will get more total bias which could be better in sonic performance.

My curious is, should I just put more mosfet in parallel (with source and gate resistors) and don't have to adjust any surrounding component? Or do I have to change the output resistors or source resistors value?

Thank you in advance for every answer.

 

[Zen Mod]

be specific about number of outputs , then I can be specific about output resistors

in fact , just take it's value (sense resistor group) as all source resistors in parallel

 

[tanwa]

be specific about number of outputs , then I can be specific about output resistors

in fact , just take it's value (sense resistor group) as all source resistors in parallel

I plan to use 10 devices per channel (5 for current source and 5 for gain)that will give me around 3 A bias?

 

[Zen Mod]

as is , with 1R source resistors , that will be 0A5 per vertical pair

so original, having 3 verticals , that is 1A5 Iq

with your 5 verticals , that will be 2A5

with 5 verticals, each source resistor 1R, you need 71mOhm in sense group , to stay in same guidelines

 

[tanwa]

as is , with 1R source resistors , that will be 0A5 per vertical pair

so original, having 3 verticals , that is 1A5 Iq

with your 5 verticals , that will be 2A5

with 5 verticals, each source resistor 1R, you need 71mOhm in sense group , to stay in same guidelines

What if I use the same value for source resistors and output resistors. What gonna happen?

 

[Zen Mod]

as far as I'm concerned , you can use 100R resistors in sense group , but parallel them just enough to get 71mOhm

 

[tanwa]

as far as I'm concerned , you can use 100R resistors in sense group , but parallel them just enough to get 71mOhm

What if I use the same value? For source resistors. And if I use same value and number of output resistors?

 

[Zen Mod]

clarify that

and post your reference schematic here , just to be sure that we are on same page

 

[tanwa]

clarify that

and post your reference schematic here , just to be sure that we are on same page

Could I put it like this?

An externally hosted image should be here but it was not working when we last tested it.

 

[Zen Mod]

yes

but as I told you - make value of these resistor at output around 70mOhm

 

[tanwa]

yes

but as I told you - make value of these resistor at output around 70mOhm

Could you explain more, How did you get 71mOhm from? Please explain a bit how to calculate this number.
Sorry, I am confusing.

 

[Zen Mod]

just find on internet how to calculate value of paralleled resistors

as on picture (4 paralleled 0R47) there is 0R1175

btw. that picture is wrong - 0R1175 is adequate for 3 vertical pairs , as in original Aleph 5

with 5 vertical pairs , as I said , there must be 71mOhm

 

[tanwa]

just find on internet how to calculate value of paralleled resistors

as on picture (4 paralleled 0R47) there is 0R1175

btw. that picture is wrong - 0R1175 is adequate for 3 vertical pairs , as in original Aleph 5

with 5 vertical pairs , as I said , there must be 71mOhm

I got it, Thank you very.